Inliners International Forums General Discussion Blown and Injected snowman4839 turbo build

One other thing you may want to really think about and that is a Safety bell housing.Your legs will thank you for it If anything bad ever happened to the clutch.

Is that bellhousing really necessary? I mean it's no 600hp+ car

Tentative parts list
Forged Pistons + rings + wrist pins - $560
http://12bolt.com/250292_products/pistons

Lump port kit - $60
http://12bolt.com/250292_products/bolt_in_lump_kits

Medium Lift Turbo Cam - $250
http://12bolt.com/250292_products/camshafts

1.94/1.6 Valves and head rebuild kit - $205
http://12bolt.com/250292_products/cylinder_heads_and_rocker_arms

Replace all major bearings (main, rod, and cam)
http://www.summitracing.com/parts/SLP-4124MA/ mains - $60
http://www.summitracing.com/parts/KGB-CR624AM/ rods - $25
http://www.summitracing.com/parts/SLP-1557M/ cam - $26

Don't know if I need lifters, pushrods, and rockers?

Machine work - zero deck the block, bore cylinders .040" over, press all new pistons into the rods, install new cam bearings, cut head for larger valves, might have them install lumps?, maybe need align hone?

Do I have any options on pistons besides the ones from Tom? It says if the block is 0 decked, the CR will be 9.44-9.87. That seems too high for a turbo engine and like I'll just run into detonation problems again with more melted pistons (even with an intercooler)? It seems like I remember turbo engines should be in the 8.5 to 9.0 at the highest.

To use those pistons, open up the combustion chamber and don't zero deck the block. This will lower the compression.

My cams come with lifters.

Sorry to hear of the busted parts. How did you hurt the leg? Take it easy on it. Tom

A better choice would be to zero the deck & mill out the pistons if that is possible.
This will decrease the chances of detonation. Plus it will make more power.

It would be better to use the correct pistons.

Mike Kirby has the correct pistons to use for your application.

MBHD

snowman4839
Active BB Member


Registered: 03-26-2010
Posts: 395
Loc: Memphis, TN Is that bellhousing really necessary? I mean it's no 600hp+ car

It doesn't take 600hp+ to take off your leg.I once had a Vary good High school friend who lost his legs from a Stock 396 4speed car. When the clutch came apart and up through the floor boards came the peice of the disk.When i used to race up in NY. the tracks there din't care if it was a 1hp motor if it had a stick It had better have a blow proof bell housing. When I got down here to Fla. I was surprized That when i asked the guys running the track (first yr for their street nats.) I asked if i needed a safety bell housing,they said if it didn't run the numbers they didn't care/meaning no. Which I thought was vary Odd. But no matter I run one.Esp.I Riped apart 3!!! pressure plates and One Cut the Nose right off my starter When the straps on it Broke the rivits. But seeing is Knowing what can Happen.Been there done that and Have seen it first hand.
I don't know about you But I happen to Like my legs vary much.
So even when my 250 was pretty much stock and knowing I was going to taking it to the track Or Getting on Hard,That was one of the first things I changed is the bell housing.
Hp is not what hurts It's the RPMs and a weak part.

So all I am trying to tell you is think about it.

Well then I'll just add that to the list of parts then. Hopefully I won't break any more bones in my leg lol.

Do ya'll have one you could link me to? Does it have to be made specific for the 250 or is just any blow-proof housing that'll hook up to a chevy engine and a 4 speed?

Lakewood. Either from Jegs Or sumit.Same as SBC

The new Quick Time bell housing is also a slick little unit.
I am going to be using one on my application. I have a Lakewood non SFI rated one right now, still better than the OEM aluminum part.

I have seen first hand the shrapnel storm from a clutch letting go. No a pretty sight.

Paul

Two pedals might be easier but three pedals are way more fun. Stick with the three.

Depends, if you want to go fast & consistant, go w/a auto.

Remember, Snowman, you want to beat your dads 400, how are you going to feel after he beats you on the launch & you miss a shift?

Snowman is running a 4 spd. BTW.

It is a lot harder to launch under boost w/a stick.

Just something to think about.

MBHD

I have to agree here sticks are funner but in general I have always felt autos just work better with turbos.

Snowman,

T.T.T.


MBHD

is it soup yet?-got her running again yet?

I hope he gets it running soon to lay the smack down on those pesky V-8 thingys.


MBHD

Well I just finished up school and started the summer. I also just ordered all the replacement parts to get here running again. Now I'm going to have a good rebuilt stock engine with a solid fuel system. Also with my graduation presents, I should be able to look into getting a J&S safegaurd and an intercooler kit.

However I ordered a set of rings and I've run into a problem. The replacement piston I ordered that should be stock size, shape, and bore calls for 5/64" compression rings and a 3/16" oil ring. The problems is that I tried putting those rings on my stock pistons which I assumed would be the same size and they don't fit. I took some calipers and the stock compression rings were apparently 4/64" (1/16") and the supposed stock replacement piston calls for 5/64" which is what I ordered. Would wear rub that ring down 1/16" or carbon build up on the piston prevent the new ring from fitting? What's the deal?

There are different size piston rings. Need to order correct size rings.

My friend you can order the J&S set-up is good friends w/the owner of J&S, here is his website. http://www.american-pi.com/corvair/corvhome.html

His name is Ray & can tell you which sytem will work for you & can help you w/any questions.

MBHD

Well the set I ordered has 5/64" first and second compression rings and 3/16" oil rings. Is that not the stock ring size?

I'll be sure to talk to him when I decide to order.

I can't remember off hand but,, IIRC, there are two sizes that came on 250 pistons.

I had ordered a set of rings when I was 16 years old & they were too thick. It said they were for a 250 engine, but I think they were a truck 250 engine? (Never looked futher into it)

Get this,,,, being young & foolish, I used my piston ring groove cleaner tool & actually machined the grooves wider so the rings fit on the pistons. DO NOT DO THIS!

I put the engine back together & it had so much blow by it was ridiculous.Probably installed the oil control rings in wrong. Live & learn.
The engine ran fine believe it or not, but it just had massive blow by.
People driving in there cars & would be @ a stop light would say to me, hey, your engine is smoking.
MBHD

Yeah it turns out that 70+ rings were 5/64 and 66-70 rings were 1/16" in 250s (but apparently 230s were still 5/64).

So anyway, apparently I'll still be able to use those 5/64 rings on that one replacement piston I bought but now I need to decide what do to with the other pistons' rings. My options are
1) Reuse the 23,000 mile rings that are already on there
2) Buy the only set of 1/16 I can find on ebay but they're Moly rings instead of the original cast iron that's going on the replacement piston.

It seems smarter to just reuse the original pistons and just hone that one cylinder for the new rings on the replacement piston to seat correctly.

If one piston has broken the others are not far behind. In fact they are cracked and you cannot see it. Save your money to build it right.

I just went ahead and bought a new set of 6 standard bore sealed power pistons that use the new 5/64" rings I have. Now I gotta wait for THOSE to ship :-/...

Would ya'll suggest I put my money into getting the J&S safeguard or an intercooler?

A J&S would be my suggestion.

Look @ what happened to your engine from detonation you heard & could not hear.

When running a turboed engine boost is addicting & you will want more & more boost, I saw it when you were running 15 psi, you could hardly contain yourself.

Well I might have to get the intercooler actually. I have to have this car running by the end of the summer and the rebuild is eating up most of my funds and since the intercooler setup costs half of the J&S, I might have to get that instead.

I wasn't "addicted" to running more and more boost. When I was running 15psi, that was the first night I had the turbo running and I also didn't have the wastegate hooked up correctly. I had it set to 3psi at first and that didn't do much so I changed it to 9psi and left it there the entire time.

That is fine getting the intercooler. That is much better than no intercooler & running 87 octane.

Did you finish your dual fuel system?

How was your 4 speed working, did you get reverse working?

Post some pics of your pistons when you get them.

You may say you are not addicted to more boost, but just wait.......

Have fun on your build. Ask any Q's if you need to.

MBHD

I WASN"T RUNNING 87 OCTANE!!!!! lol. I ran 93 in every tank since I put on the turbo.

I am working on getting the fuel cell mounted which is the only hard part. All of the plumbing mounts to the fuel cell cage so it'll be a painless process.

Just before I took out the engine, I got the 4 speed working all the way. I have the 4 speeds up on the tree and it works extremely well. Shifts smooth, doesn't grind except for shifting back into first going like 15+mph which kinda stinks. Just like I said, I got the reverse working by simply setting a metal rod connecting to the reverse ear linkage. All I have to do to shift into reverse is set the 4 speeds on the tree into reverse and push on that lever and it's in reverse. Pull on the lever and it's back in neutral and use the tree for all the forward gears.
I tried using a pull cable instead of the solid lever but it didn't have enough leverage and it was just a failure in general but with the solid lever, everything works great!

The pistons should get here this coming week, I will.

I will. It's always fun the second or third time :-))

You should @ least get a BTM along w/your intercooler.

Hotter spark. more complete burn of your fuel.
Examples:
http://www.ebay.com/itm/Universal-MSD-Ig...7ed4c0a&vxp=mtr

http://www.ebay.com/itm/MSD-Boost-Timing...1e98323&vxp=mtr

http://www.ebay.com/itm/MSD-BOOST-TIMING...7b917e3&vxp=mtr

http://compare.ebay.com/like/400301135588?var=lv<yp=AllFixedPriceItemTypes&var=sbar

http://autoplicity.com/products/95969-MS...CFYYZQgodxFm4UA

It cannot retard the timing when the engine knocks, it will retard the timing referencing off of boost pressure, that way, you can run advanced timing when cruising & getting better mileage, but when you are in boost mode, it will retard the timing & hopefully save your engine. (cross your fingers)

MBHD

Some pictures of the pistons

Those pistons scare me. Look inside and see the steel struts cast in to them to control expansion. they are the cause of stress risers which can lead to cracked and broken skirts which can lead to engine failure.

I much prefer hypereutectic pistons for their strength and dimensional stability without the use of steel struts. Save the cast ones for a stock rebuild.

X2, those pistons will have less compression than your stock original pistons. Like 8.0:1 Those will make your engine even more lazy & come up on boost even slower than before w/your old set-up.

I also do not like the big chamfer on the top side of the piston where it will be more exposed to detonation.

Sorry to give you the bad news.


MBHD

I understand that they aren't the best choice but I don't have the money to re-buy pistons and I need to have this engine running by the end of next month so I'm kinda forced to use these.

To raise the compression back up, can I have the head shaved some?

on a brighter note, I got the fuel cell installed and all I have to do is run the line to the carb.

Looking good man keep up the work when I get my nova here and back together we will have to cruise sometime

Snowman,

You can mill the cyl head to raise the compression a bit, but, just my opinion, this build is going in the wrong direction, I do understand about no $ & little time to get it all back together.So sometimes you need to compromise just to get your car running, been there done that.

These would have been a little bit better choice, but they are still cast pistons.
http://www.ebay.com/itm/Chevy-307-Sealed...42bfc8a&vxp=mtr

I would definately lower the boost down to 3-5 PSI.
Just because you have no intercooler, no methanol injection, no MSD boost retard or simular set-up. Also, you are using cast pistons.

Curious as to what octane fuel are you going to use for the fuel cell?
Is that a 10 gallon cell?

MBHD

It's a 8 gallon cell and I'm going to put 93 in both the cell and the original tank unless I go to the track in which case I'll be putting race gas in the cell.

Snowman,
how is the build going so far?

Where you going w/an intercooler, or BTM, this time around?


MBHD

Just got the parts to a machine shop yesterday. Having them install cam bearings, install the new pistons, and gap the rings a little larger than stock for the higher heat of a turbo engine. Should be done in a week or two.

I should have enough money after everything for a basic intercooler setup but I'm mostly focused on getting it running before I go off to college in august.

I don't think I'm going to get a BTM, I'm just going to save up for a little longer and get that J&S knock box that includes the boost reference so it functions like the BTM.

Hey can one of yall link me to a set of cam bearings for my 69 250. I bought a sealed power set from Summit and the machine shop just called and said 2 of the bearing seats have different size bores so I need buy a different set.

You need to quit relying on summit. Those guys will sell you all the wrong parts you are willing to buy.
Why not buy the parts from your local machine shop that is installing them?
Prior to 70 used one set and after used another.
I like to use Clevitte bearings for the cam.
Clevite 399s for early engines
clevite sh718s for later engines

Well Summit has been pretty helpful with everything I've had to replace on an easy-to-use website. They've also been great about returns. I had to return a flywheel and I talked them into giving me a complete refund because they listed it somewhat confusingly on their site.

I dd just go ahead and order the clevite 399s which I'll get to the machine shop ASAP